As one type of combined cycle power generation plant that drives a generator using a gas turbine and a steam turbine, there is a power generation plant in which a shaft of the gas turbine is connected to one end of a shaft of the generator and a shaft of the steam turbine is connected to the other end of the shaft of the generator. In this type of the combined cycle power generation plant, the shaft of the gas turbine, the shaft of the generator, and the shaft of the steam turbine are aligned in the same straight line.
In this type of the combined cycle power generation plant, when an inspection of the shaft and the like is carried out after taking out the shaft of the generator from a casing of the generator, the inspection is sometimes carried out using the following method, for example. First, one of the gas turbine and the steam turbine that exist in an axial direction of the generator is disassembled. Next, after lifting up the generator, the shaft of the generator is pulled out from the casing of the generator toward a side, in the axial direction of the generator, on which an empty space has been created as a result of the disassembly. After that, the shaft is placed in a predetermined location, and the inspection of the shaft and the like is carried out.
In the above-described method, when disassembling the generator, it becomes necessary to disassemble the gas turbine or the steam turbine. Thus, with the above-described method, even when only the generator needs inspection, it is necessary to disassemble the gas turbine or the steam turbine.
Here, Patent Literature 1 described below discloses the following method in which it is not necessary to disassemble the gas turbine or the steam turbine when disassembling the generator. In this method, two platforms are prepared in advance, each of which has a floor face at a position higher than the highest point of the steam turbine. Then, of the two platforms, the first platform is installed so that the floor face of the first platform is positioned above the steam turbine. Next, the shaft of the generator is disconnected from the shaft of the gas turbine, and at the same time, the shaft of the generator is disconnected from the shaft of the steam turbine. Next, the generator is lifted up using a special lift-up device, until a bottom of the generator reaches a higher position than the floor face of the first platform. Next, the second platform is installed below the generator, and the generator is placed on the second platform. Next, the shaft of the generator is pulled out from the generator placed on the second platform toward the first platform side in the axial direction of the shaft. After that, the shaft is placed on the first platform, and the inspection of the shaft and the like is carried out.